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Message-ID: <696dbfdc-1b08-446d-8983-dda09d861f59@linux.intel.com>
Date:   Tue, 17 Oct 2023 09:10:31 +0300
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Subject: Re: [PATCH 2/5] i3c: add actual in i3c_priv_xfer
To:     Frank Li <Frank.Li@nxp.com>, alexandre.belloni@bootlin.com,
        miquel.raynal@bootlin.com, conor.culhane@silvaco.com,
        joe@perches.com, linux-i3c@lists.infradead.org,
        linux-kernel@vger.kernel.org, imx@lists.linux.dev
References: <20231016154632.2851957-1-Frank.Li@nxp.com>
 <20231016154632.2851957-3-Frank.Li@nxp.com>
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From:   Jarkko Nikula <jarkko.nikula@linux.intel.com>
In-Reply-To: <20231016154632.2851957-3-Frank.Li@nxp.com>
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Hi

On 10/16/23 18:46, Frank Li wrote:
> In MIPI I3C Specification:
> 
> "Ninth Bit of SDR Target Returned (Read) Data as End-of-Data: In I2C, the
> ninth Data bit from Target to Controller is an ACK by the Controller. By
> contrast, in I3C this bit allows the Target to end a Read, and allows the
> Controller to Abort a Read. In SDR terms, the ninth bit of Read data is
> referred to as the T-Bit (for ‘Transition’)"
> 
> I3C allow devices early terminate data transfer. So need "actual" field to
> indicate how much get by i3c_priv_xfer.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>   include/linux/i3c/device.h | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h
> index 90fa83464f00..f2fa7ee5d96d 100644
> --- a/include/linux/i3c/device.h
> +++ b/include/linux/i3c/device.h
> @@ -66,6 +66,7 @@ struct i3c_priv_xfer {
>   		void *in;
>   		const void *out;
>   	} data;
> +	u16 actual;
>   	enum i3c_error_code err;
>   };
>   
Would this be more clear if named as "actual_len" and put next after 
"len" field in this structure? Also kerneldoc comment is missing.